اثربخشي واكسن هپاتيت B در دانشجويان دانشكده علوم پزشكي شاهرود در سال 1383

Efficacy of Hepatitis B Vaccine in the Students of Shahrood University of Medical Sciences in 2004

Hepatitis B is considered as one of the occupational diseases. Health care workers and the students of health sciences are commonly exposed to this infection. With regards to the importance of hepatitis B vac¬cination as a preventive method and the measuring titer of anti-HBsAg in high risk groups on one hand and because of the fact that optimal response to a vaccine depends on multiple factors including the nature of the vaccine and the immunity status of the recipients on the other hand, a serological survey was conducted among the students of health sciences in Shahrood faculty of medical sciences to find out about their responses to the booster dose.In a cross sectional study, anti-HBsAg of 150 students of health sciences who were vaccinated against hepatitis B (Heberbiovac-HB) was tested using Elisa method.The anti-HBsAg of less than 10 mlu/mg was defined as a low efficacy. All the completed a structured questionnaire that assessed the demo¬graphic characteristics as well as the affecting factors including: the intervals between the three doses of the vaccine injection, the previous immuneity system deficiency, and the use of drugs causing immunity deficiency. Anxiety as an affecting factor was determined with MMPI (the Minnesota Multiphasic Personality Inventory). The data were statistically analyzed using the student t-test, chi-square, Fisher exact test, linear Regression and non parametric test.8 (5.3%) of 150 students of health sciences had low efficacy. There were no statistical differences in the means of the intervals between neither the first and the second, nor the second and the third doses of vac¬cine injections. There was no significant difference in terms of the use of drugs affecting immunity system and anxiety, neither The time interval between the third dose of vaccine injection and the measurement of anti-HBsAg was greater in the group with low efficacy (24.1 ± 20.2 month vs 40.6± 24.6 month P<0.05). Using Regression test, a meaningful relation has been found to exist between the increasing of time interval and the decreasing of the anti-HBsAg titer (r=-0.266 P0.001). Anti-HBsAg showed to arise after the booster dose injection(p<0.001).Efficacy of Heberbiovac-HB vaccine was achieved in 94.7% of the cases. It is as efficient as the efficacy of common hepatitis B vaccine in the world comprising: Engerix-B and Recombivax-HB. The results show a relation between the passing of time and the decreasing of antibody tire. Also, a high level of ef¬ficacy has been achieved after the injection of booster dose in the students with low level of efficacy. With regards to the high susceptibility and the risk of clinical hepatitis B among the students of medical sciences, a serological survey is recommended for all such students after vaccination of three doses of hepatitis B as well as the repeat the antibody titer in the high risk groups.